Problems with blog archives

This is a new one for me. I have used enfold several times and never run into this problem. When accessing posts through the archives, I get the following error displayed on screen.

Warning: First parameter must either be an object or the name of an existing class in /home/nspt4kids/public_html/wp-content/plugins/custom-widget-area/includes/class.CUSTWIDGETSidebars.php on line 118

You can see it live here…
http://nspt4kids.com/2014/03/

Anyone run into this? What is really weird is that the same sidebar works as expected on all pos pages and all other categorical list pages. Only in the archives is where things get f’d.

Thanks if you can help!
Mike